<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Filter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: StringTrim.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Filter_Interface
 */
require_once 'Zend/Filter/Interface.php';

/**
 * @category   Zend
 * @package    Zend_Filter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Filter_StringTrim implements Zend_Filter_Interface {
	/**
	 * List of characters provided to the trim() function
	 *
	 * If this is null, then trim() is called with no specific character list,
	 * and its default behavior will be invoked, trimming whitespace.
	 *
	 * @var string|null
	 */
	protected $_charList;
	
	/**
	 * Sets filter options
	 *
	 * @param  string|array|Zend_Config $options
	 * @return void
	 */
	public function __construct($options = null) {
		if ($options instanceof Zend_Config) {
			$options = $options->toArray ();
		} else if (! is_array ( $options )) {
			$options = func_get_args ();
			$temp ['charlist'] = array_shift ( $options );
			$options = $temp;
		}
		
		if (array_key_exists ( 'charlist', $options )) {
			$this->setCharList ( $options ['charlist'] );
		}
	}
	
	/**
	 * Returns the charList option
	 *
	 * @return string|null
	 */
	public function getCharList() {
		return $this->_charList;
	}
	
	/**
	 * Sets the charList option
	 *
	 * @param  string|null $charList
	 * @return Zend_Filter_StringTrim Provides a fluent interface
	 */
	public function setCharList($charList) {
		$this->_charList = $charList;
		return $this;
	}
	
	/**
	 * Defined by Zend_Filter_Interface
	 *
	 * Returns the string $value with characters stripped from the beginning and end
	 *
	 * @param  string $value
	 * @return string
	 */
	public function filter($value) {
		if (null === $this->_charList) {
			return $this->_unicodeTrim ( ( string ) $value );
		} else {
			return $this->_unicodeTrim ( ( string ) $value, $this->_charList );
		}
	}
	
	/**
	 * Unicode aware trim method
	 * Fixes a PHP problem
	 *
	 * @param string $value
	 * @param string $charlist
	 * @return string
	 */
	protected function _unicodeTrim($value, $charlist = '\\\\s') {
		$chars = preg_replace ( array ('/[\^\-\]\\\]/S', '/\\\{4}/S', '/\//' ), array ('\\\\\\0', '\\', '\/' ), $charlist );
		
		$pattern = '^[' . $chars . ']*|[' . $chars . ']*$';
		return preg_replace ( "/$pattern/sSD", '', $value );
	}
}
